An Intervention to Reduce Bicycle Injuries among Middle School Students in Rural China

This study aimed to evaluate the effectiveness of an intervention to reduce bicycle injuries among rural middle school students in China. A one-year cluster-randomized controlled trial was conducted with seventh grade students from six middle schools in two towns in rural Chaoshan, China. The two towns were randomly assigned to either the intervention or control group. Road safety education materials, two lectures on road safety, and a series of health education activities were delivered to 1312 students in the intervention group over one year, and the content of the intervention included traffic safety knowledge, methods of preventing bicycle injury and management of bicycle injuries. Questionnaires weere administered to the two groups before and after the intervention to measure the incidence, cognitions, and behaviors related to bicycle injuries. The pre-intervention incidence of bicycle injuries exhibited no significant difference between the two groups, while the difference reached significance after the intervention (χ2 = 13.409, p < 0.001). In the intervention group, the incidence decreased significantly after the intervention (χ2 = 8.137, p = 0.004), while no significant change was observed in the control group. Publicity and education intervention measures have certain short-term effects on the prevention of bicycle injuries among rural middle school students; we should approach intervention measures according to the characteristics of traffic injuries in different areas

Innovation Capacity and Entrepreneurial Intention: The Moderating Effects of Entrepreneurial Atmosphere

There is natural relationship between innovative ability and entrepreneurial intentions (EI). Surprisingly, very little attention has been given to this important issue in previous literatures. Combining innovator’s DNA model with social cognitive theory, this paper collects 1263 samples to test the complex link between innovative capacity (operationalized as IC) and EI of potential entrepreneur. In addition, the effects of perceived entrepreneurial atmosphere (EA) on EI are examined. The results show that innovation capacity significantly affects EI, and perceived entrepreneurial desirability (ED) and feasibility (EF) mediates this relationship significantly. EA has direct effect on EI and indirectly changes the effect of IC through moderating the relationship between EF and EI. For robust test, we substitute dependent variable EI with entrepreneurial behavior and repeat the process above. The core results remain unchanged. The difference here is that actual entrepreneurial practice is not affected by attractiveness of start-up, innovator’s confidence to succeed in it is more important. This research confirms the necessary link between innovative capacity and EI, and substantially improves theexplaining efficacy of classical EI models based on personality traits. Our findings indicate that policymakers need to pay more attention to training and improving potential entrepreneurs’ innovative ability and create social atmosphere more suitable for innovators entering the process of starting a new venture. Through increasing attractiveness and the simplicity to be an entrepreneur, government can motivate innovators to be more willing to start a business and also help them succeed at ease

Effect of Annealing Process and Molecular Weight on the Polymorphic Transformation from Form II to Form I of Poly(1-butene)

Poly(1-butene) (PB-1) resin has excellent mechanical properties, outstanding creep resistance, environmental stress crack resistance and other excellent properties. However, PB-1 resin experiences a crystal transformation for a period, which seriously affects the production efficiency and directly restricts its large-scale commercial production and application. The factors affecting the crystal transformation of PB-1 are mainly divided into external and internal factors. External factors include crystallization temperature, thermal history, nucleating agent, pressure, solvent induction, etc., and internal factors include chain length, copolymerization composition, isotacticity, its distribution, etc. In this study, to avoid the interference of molecular weight distribution on crystallization behavior, five PB-1 samples with narrow molecular weight distribution (between 1.09 and 1.44) and different molecular weights (from 23 to 710 k) were chosen to research the influence of temperature and time in the step-by-step annealing process and molecular weight on the crystal transformation by differential scanning calorimetry (DSC). When the total annealing time was the same, the step-by-step annealing process can significantly accelerate the rate of transformation from crystal form II to I. PB-1 samples with different molecular weights have the same dependence on annealing temperature, and the optimal nucleation temperature (i.e., low annealing temperature, Tl) and growth temperature (i.e., high annealing temperature, Th) were −10 °C and 40 °C, respectively. At these two temperatures, the crystal form I obtained by step-by-step annealing had the highest content; other lower or higher annealing temperatures would reduce the rate of crystal transformation. When the annealing temperature was the same, crystal form I first increased with annealing time tl, then gradually reached a plateau, but the time to reach a plateau was different. The crystalline form I contents of the samples with lower molecular weight increased linearly with annealing time th. However, the crystalline form I contents of the samples with higher molecular weight increased rapidly with annealing time th at the beginning, and then transformation speed from form II to form I slowed down, which implied that controlling Tl/tl and Th/th can tune the different contents of form I and form II. At the same Tl/tl or Th/th, with increasing molecular weight, the transformation speed from form II to form I via the step-by-step annealing process firstly increased and then slowed down due to the competition of the number of linked molecules and molecular chain mobility during crystallization. This study definitely provides an effective method for accelerating the transformation of poly(1-butene) crystal form, which not only has important academic significance, but also has vital industrial application

Effect of Annealing Process and Molecular Weight on the Polymorphic Transformation from Form II to Form I of Poly(1-butene)

Poly(1-butene) (PB-1) resin has excellent mechanical properties, outstanding creep resistance, environmental stress crack resistance and other excellent properties. However, PB-1 resin experiences a crystal transformation for a period, which seriously affects the production efficiency and directly restricts its large-scale commercial production and application. The factors affecting the crystal transformation of PB-1 are mainly divided into external and internal factors. External factors include crystallization temperature, thermal history, nucleating agent, pressure, solvent induction, etc., and internal factors include chain length, copolymerization composition, isotacticity, its distribution, etc. In this study, to avoid the interference of molecular weight distribution on crystallization behavior, five PB-1 samples with narrow molecular weight distribution (between 1.09 and 1.44) and different molecular weights (from 23 to 710 k) were chosen to research the influence of temperature and time in the step-by-step annealing process and molecular weight on the crystal transformation by differential scanning calorimetry (DSC). When the total annealing time was the same, the step-by-step annealing process can significantly accelerate the rate of transformation from crystal form II to I. PB-1 samples with different molecular weights have the same dependence on annealing temperature, and the optimal nucleation temperature (i.e., low annealing temperature, Tl) and growth temperature (i.e., high annealing temperature, Th) were −10 °C and 40 °C, respectively. At these two temperatures, the crystal form I obtained by step-by-step annealing had the highest content; other lower or higher annealing temperatures would reduce the rate of crystal transformation. When the annealing temperature was the same, crystal form I first increased with annealing time tl, then gradually reached a plateau, but the time to reach a plateau was different. The crystalline form I contents of the samples with lower molecular weight increased linearly with annealing time th. However, the crystalline form I contents of the samples with higher molecular weight increased rapidly with annealing time th at the beginning, and then transformation speed from form II to form I slowed down, which implied that controlling Tl/tl and Th/th can tune the different contents of form I and form II. At the same Tl/tl or Th/th, with increasing molecular weight, the transformation speed from form II to form I via the step-by-step annealing process firstly increased and then slowed down due to the competition of the number of linked molecules and molecular chain mobility during crystallization. This study definitely provides an effective method for accelerating the transformation of poly(1-butene) crystal form, which not only has important academic significance, but also has vital industrial application

Triboelectric Nanogenerators: State of the Art

The triboelectric nanogenerator (TENG), as a novel energy harvesting technology, has garnered widespread attention. As a relatively young field in nanogenerator research, investigations into various aspects of the TENG are still ongoing. This review summarizes the development and dissemination of the fundamental principles of triboelectricity generation. It outlines the evolution of triboelectricity principles, ranging from the fabrication of the first TENG to the selection of triboelectric materials and the confirmation of the electron cloud overlapping model. Furthermore, recent advancements in TENG application scenarios are discussed from four perspectives, along with the research progress in performance optimization through three primary approaches, highlighting their respective strengths and limitations. Finally, the paper addresses the major challenges hindering the practical application and widespread adoption of TENGs, while also providing insights into future developments. With continued research on the TENG, it is expected that these challenges can be overcome, paving the way for its extensive utilization in various real-world scenarios